I would suggest you download something readymade from GitHub that is built upon the architecture you already know and understand.
Always ask yourself: What are you going to do with it! An ECommerce Site is something BIG!! As soon as real money comes in, you have to do it professionally. Just trying when it comes to real money is a risk!

I would go with woocommerce and WordPress I’ve used it before. I’ve used it and others before. It works, it works fast and while e–commerce is hardly ever simple, this helps simplify while still giving you all the options you need.